Insect pests are a serious problem in agriculture. They destroy millions of acres of staple crops such as corn, soybeans, peas, and cotton. Yearly, these pests cause over $100 billion dollars in crop damage in the U.S. alone. In an ongoing seasonal battle, farmers must apply billions of gallons of synthetic pesticides to combat these pests. Other methods employed in the past delivered insecticidal activity by microorganisms or genes derived from microorganisms expressed in transgenic plants. For example, certain species of microorganisms of the genus Bacillus are known to possess pesticidal activity against a broad range of insect pests including Lepidoptera, Diptera, Coleoptera, Hemiptera, and others. In fact, microbial pesticides, particularly those obtained from Bacillus strains, have played an important role in agriculture as alternatives to chemical pest control. Agricultural scientists have developed crop plants with enhanced insect resistance by genetically engineering crop plants to produce insecticidal proteins from Bacillus. For example, corn and cotton plants genetically engineered to produce Cry toxins (see, e.g., Aronson (2002) Cell Mol. Life Sci. 59(3):417-425; Schnepf et al. (1998) Microbiol. Mol. Biol. Rev. 62(3):775-806) are now widely used in American agriculture and have provided the farmer with an alternative to traditional insect-control methods. However, these Bt insecticidal proteins only protect plants from a relatively narrow range of pests. Moreover, these modes of insecticidal activity provided varying levels of specificity and, in some cases, caused significant environmental consequences.
Previous control of stinkbugs relied on broad spectrum insecticides. With the adoption of transgenic controls for major lepidopteran pests in several crops, these insecticides are no longer used and stinkbugs have become a major secondary pest. No successful use of transgenic control of stinkbugs has been described or adopted. This may be due in part to the extra oral digestion employed by stinkbugs where digestive enzymes are injected into the host plant prior to feeding. This makes it difficult to find proteins that survive long enough to manifest activity against these insects. RNAi may overcome that feeding behavior by relying on double stranded RNAs rather than proteins. Thus, there is an immediate need for alternative methods to control pests.